Electrical property dominated promising half-Heusler thermoelectrics through high-throughput material computations

Half-Heusler (HH) compounds are one of the state-of-the-art thermoelectric materials with high electrical properties. Here, we carry out high-throughput computations on 95 HH compounds. Using the thermoelectric properties of NbFeSb and ZrNiSn as the screening criterion, we filter out nine p-type and six n-type promising candidates with environmentally friendly elements. Scrutinizing their electronic structures, we find that the cooperative effects of high band degeneracy, small deformation potential, light band, and large phonon velocity contribute to the large power factor. It is interesting to notice that the electrical properties dominate the thermoelectric performance in HH compounds. Balancing the excellent electrical properties and relatively low thermal conductivities, three HH compounds are predicted to be promising thermoelectric candidates. Our work not only provides novel promising materials for future experimental investigation but also offers insights into understanding the underlying physical nature of high thermoelectric performance.